1. Field
The present disclosure relates to transparent conductive thin films and electronic devices including the same.
2. Description of Related Art
Electronic devices such as flat panel displays (e.g., a liquid crystal display and a light emitting diode display), touch panel screens, photovoltaic cells, and transparent transistors include transparent electrodes. It is desirable for materials of the transparent electrode to have high transmittance (e.g., at least 80%) and low specific resistivity of 1×10−3 or lower. The currently available materials for the transparent electrode include indium tin oxide (ITO), tin oxide (SnO2), zinc oxide (ZnO), and the like. The ITO is an n-type semiconductor having electrons and oxygen vacancies generated by SnO2. Electrical and optical characteristics of the ITO may depend on the defects in the crystalline In2O3 structure. The ITO may include a solid solution compound being composed of In2O3 at 90 wt % and SnO2 at 10 wt %, and may exhibit a high level of carrier concentration. However, ITO tends to have poor flexibility. Also, limited reserves of indium may lead to an increasing cost thereof so that it is desirable to develop a material that may substitute for the ITO. Tin oxides (e.g., SnO2) are less expensive and chemically stable but may not be etched easily. Also, the resistivity of tin oxides may be higher than that of indium oxide and zinc oxide, and a high process temperature may be used with tin oxides. Zinc oxide is reported to have transmittance and electrical conductivity that are comparable to those of ITO, but zinc oxide may be chemically unstable and may not provide a high etching ratio and a well defined pattern when it is subjected to a wet etching process. The above-discussed transparent electrode materials have specific resistivity of about 1×10−4 to 4×10−4 Ωcm.
Recently, there has been a growing demand for flexible displays or ultra high definition (UHD) displays so that it is desirable to develop novel materials for transparent electrodes, enabling the realization of a lower level of specific resistivity together with high transmittance.